Errors in Sampled Data Phase Measurement

Synchronous real-time sampling can be used to measure the phase angle ϕ between two sine waves in a relatively low-frequency range. The data samples are acquired by a microcomputer-based system, then manipulated to determine ϕ. The system uses less hardware than a traditional phase meter, however there will be an error in ϕ due to mislocating the zero-crossings of the two sine waves. An error analysis is given, which indicates that errors mainly depend on signal amplitudes, number of quantization bits, and number of samples per cycle. Also, numerical results are illustrated.